The triaxial cell is pressurized and the load frame begins its steady downward travel. Pore pressure transducers record the response while the data acquisition system plots deviator stress against axial strain in real time. For Belleville Ontario projects, this sequence runs dozens of times each week in our soils laboratory. The city sits on a complex glacial stratigraphy where grey silty till overlies fractured limestone of the Lindsay Formation at depths ranging from 4 to 12 meters. These materials demand a soil mechanics study that goes beyond index properties. Shear strength parameters, consolidation characteristics, and permeability coefficients must be measured directly because the till matrix contains lenses of varved clay that behave very differently under load than the surrounding material. A CPT test often provides the in-situ stratigraphic resolution needed before selecting undisturbed sample locations for laboratory triaxial work.
Effective stress parameters from consolidated-undrained triaxial testing on Belleville glacial till typically show a friction angle between 28 and 33 degrees with cohesion intercepts of 5 to 15 kPa.
